DISK SUBSTRATE, DEVICE FOR PRODUCTION OF DISK SUBSTRATE AND PRODUCTION OF DISK SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a disk substrate, a device for the production of the disk substrate and a method for the production of the disk substrate, that burrs on the outer circumference of a resin disk substrate is prevented. ;SOLUTION: In this method, for example, an amorphous polyolefin resin is used and molded into a disk substrate under the conditions of (1) 105 to 125°C die temp. (the temp. of the molding dies), (2) 0.23 to 0.45 sec filling time, (3) 34.5 to 40.2 kgf/cm2 pressure range kept in the process, (4) 300 to 330°C resin temp. and (5) ±5°C die temp. difference (the temp. difference between the movable die and the fixed die), so that the length x and thickness y of burrs on the circumference satisfy the relation of yx or y20 μm.;COPYRIGHT: (C)2000,JPO